Bob writes: good stuff clipped.. ..and the vacuum behind it : makes the bullet effectively longer. : The bullet plus it's shockwave plus it's vacuum is now : displacing the fluid in the can nearly instaneously! in addition to that, the water component exiting the entry hole in such a low pressure wake effectively boild and vapourises, remembering substances boil at high temperatures OR low pressures :) A .270 rifle bullet at Mach 4 hitting a water : melon is quite impressive. Ever tried a 220 swift (4100 fps) or a 22.250 (3800 fps)? Not a lot of force in comparison but at those sorts of velocities things get pretty weird. I put a few '250's through some 1/2 inch plate steel - amazing effect. The hole appeared melted through with liquid looking 'splash' marks around the entry and exit points, the ground behind the plate was silvery for about 2 meters with what looked like a fine iron mist. The ground in front of the muzzle showed a patern in the sand of radiated cocentric waves out to around 7 meters - headache follows - k
